Short wavelength light reflecting films from side‐chain liquid crystal homopolymers with chiral spacers

Abstract

A series of acrylate monomers with alkoxy tails of varying lengths are synthesised and polymerised. The butoxy analogue had a stable enantiotropic cholesteric liquid crystalline phase which formed a grandjean texture when prepared as a thin film between glass slides. The polymer was mixed with a low molar mass nematic liquid crystal in various proportions and the pitch of the chiral nematic phases were determined using a cano-wedge cell technique. The polymer prepared from (S)-2-(4-butoxyphenyl-4'-benzoyloxy)-1-methyl ethyl acrylate had a pitch length of 113 nm which indicates that the polymer film could be employed in optical devices requiring selective reflection of light with short wavelengths in the region of 170 nm.

Preparation of aromatic polyesters by direct polymerization in the presence of boronic anhydride under non-stoichiometric condition

“…These precipitates contained both crystal structure of the phase I and II, and the relative amount of the phase II increased with the c values. It is well known that the appearance of the phase II was attributed to the bulkiness of oligomer end-group [10,24,26]. Therefore, the increase in the relative amount of the phase II and the decrease in the crystallinity can be explained by the increase in the amount of the bulky endgroups derived from HOBA, being good agreement with the change in the DP n with the c value.…”

“…p-Hexyloxybenzoic acid (HOBA), 4-(4-hexyloxybenzoyloxy)benzoic acid (HBBA) and p-hexyloxyphenol (HOPH) were synthesized according to the previously reported procedures [16,19]. 4-(4-Hexyloxyphenoxycarbonyl)phenol (HPCP) was synthesized according to the previously reported procedure [24]. An isomeric mixture of dibenzyltoluene was obtained from Matsumura Oil Co. Ltd. (trade name: Barrel Therm 400, molecular weight: 380, boiling point: 382 C) and distilled under reduced pressure (170e175 C/ 0.3 mmHg).…”